#
# Copyright (C) 2018, 2020 Jeffery To
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#

include $(TOPDIR)/rules.mk

GO_VERSION_MAJOR_MINOR:=1.14
GO_VERSION_PATCH:=6

PKG_NAME:=golang
PKG_VERSION:=$(GO_VERSION_MAJOR_MINOR)$(if $(GO_VERSION_PATCH),.$(GO_VERSION_PATCH))
PKG_RELEASE:=1

GO_SOURCE_URLS:=https://dl.google.com/go/ \
                https://mirrors.ustc.edu.cn/golang/ \
                https://mirrors.nju.edu.cn/golang/

PKG_SOURCE:=go$(PKG_VERSION).src.tar.gz
PKG_SOURCE_URL:=$(GO_SOURCE_URLS)
PKG_HASH:=73fc9d781815d411928eccb92bf20d5b4264797be69410eac854babe44c94c09

PKG_MAINTAINER:=Jeffery To <jeffery.to@gmail.com>
PKG_LICENSE:=BSD-3-Clause
PKG_LICENSE_FILES:=LICENSE
PKG_CPE_ID:=cpe:/a:golang:go

PKG_BUILD_DEPENDS:=golang/host
PKG_BUILD_DIR:=$(BUILD_DIR)/go-$(PKG_VERSION)
PKG_BUILD_PARALLEL:=1
PKG_USE_MIPS16:=0

PKG_GO_WORK_DIR:=$(PKG_BUILD_DIR)/.go_work
PKG_GO_HOST_CACHE_DIR:=$(PKG_GO_WORK_DIR)/host_cache
PKG_GO_TARGET_CACHE_DIR:=$(PKG_GO_WORK_DIR)/target_cache

PKG_GO_PREFIX:=/usr
PKG_GO_VERSION_ID:=$(GO_VERSION_MAJOR_MINOR)
PKG_GO_ROOT:=$(PKG_GO_PREFIX)/lib/go-$(PKG_GO_VERSION_ID)

HOST_BUILD_DIR:=$(BUILD_DIR_HOST)/go-$(PKG_VERSION)
HOST_BUILD_PARALLEL:=1

HOST_GO_WORK_DIR:=$(HOST_BUILD_DIR)/.go_work
HOST_GO_CACHE_DIR:=$(HOST_GO_WORK_DIR)/cache

HOST_GO_PREFIX:=$(STAGING_DIR_HOSTPKG)
HOST_GO_VERSION_ID:=cross
HOST_GO_ROOT:=$(HOST_GO_PREFIX)/lib/go-$(HOST_GO_VERSION_ID)

HOST_GO_VALID_OS_ARCH:= \
  android_386  android_amd64  android_arm  android_arm64 \
  darwin_386   darwin_amd64   darwin_arm   darwin_arm64 \
  freebsd_386  freebsd_amd64  freebsd_arm  freebsd_arm64 \
  linux_386    linux_amd64    linux_arm    linux_arm64 \
  \
  openbsd_386  openbsd_amd64  openbsd_arm \
  netbsd_386   netbsd_amd64   netbsd_arm \
  plan9_386    plan9_amd64    plan9_arm \
  \
  windows_386  windows_amd64 \
  \
  dragonfly_amd64 \
  illumos_amd64 \
  solaris_amd64 \
  \
  aix_ppc64 \
  js_wasm \
  \
  linux_ppc64 linux_ppc64le \
  linux_mips linux_mipsle linux_mips64 linux_mips64le \
  linux_riscv64 linux_s390x

BOOTSTRAP_SOURCE:=go1.4-bootstrap-20171003.tar.gz
BOOTSTRAP_SOURCE_URL:=$(GO_SOURCE_URLS)
BOOTSTRAP_HASH:=f4ff5b5eb3a3cae1c993723f3eab519c5bae18866b5e5f96fe1102f0cb5c3e52

BOOTSTRAP_BUILD_DIR:=$(HOST_BUILD_DIR)/.go_bootstrap
BOOTSTRAP_WORK_DIR:=$(BOOTSTRAP_BUILD_DIR)/.go_work
BOOTSTRAP_CACHE_DIR:=$(BOOTSTRAP_WORK_DIR)/cache

BOOTSTRAP_GO_VALID_OS_ARCH:= \
  darwin_386     darwin_amd64 \
  dragonfly_386  dragonfly_amd64 \
  freebsd_386    freebsd_amd64    freebsd_arm \
  linux_386      linux_amd64      linux_arm \
  netbsd_386     netbsd_amd64     netbsd_arm \
  openbsd_386    openbsd_amd64 \
  plan9_386      plan9_amd64 \
                 solaris_amd64 \
  windows_386    windows_amd64

include $(INCLUDE_DIR)/host-build.mk
include $(INCLUDE_DIR)/package.mk
include ../golang-compiler.mk
include ../golang-package.mk

PKG_UNPACK:=$(HOST_TAR) -C $(PKG_BUILD_DIR) --strip-components=1 -xzf $(DL_DIR)/$(PKG_SOURCE)
HOST_UNPACK:=$(HOST_TAR) -C $(HOST_BUILD_DIR) --strip-components=1 -xzf $(DL_DIR)/$(PKG_SOURCE)
BOOTSTRAP_UNPACK:=$(HOST_TAR) -C $(BOOTSTRAP_BUILD_DIR) --strip-components=1 -xzf $(DL_DIR)/$(BOOTSTRAP_SOURCE)

# don't strip ELF executables in test data
RSTRIP:=:
STRIP:=:

ifdef CONFIG_PKG_ASLR_PIE_ALL
  ifeq ($(GO_TARGET_PIE_SUPPORTED),1)
    PKG_GO_ENABLE_PIE:=1
    PKG_GO_INSTALL_SUFFIX:=$(GO_TARGET_PIE_INSTALL_SUFFIX)
  else
    $(warning PIE buildmode is not supported for $(GO_OS)/$(GO_ARCH))
  endif
endif

ifeq ($(GO_HOST_PIE_SUPPORTED),1)
  HOST_GO_ENABLE_PIE:=1
  HOST_GO_INSTALL_SUFFIX:=$(GO_HOST_PIE_INSTALL_SUFFIX)
endif

define Package/golang/Default
$(call GoPackage/GoSubMenu)
  TITLE:=Go programming language
  URL:=https://golang.org/
  DEPENDS:=$(GO_ARCH_DEPENDS)
endef

define Package/golang/Default/description
The Go programming language is an open source project to make
programmers more productive.

Go is expressive, concise, clean, and efficient. Its concurrency
mechanisms make it easy to write programs that get the most out of
multicore and networked machines, while its novel type system enables
flexible and modular program construction. Go compiles quickly to
machine code yet has the convenience of garbage collection and the power
of run-time reflection. It's a fast, statically typed, compiled language
that feels like a dynamically typed, interpreted language.
endef

# go tool requires source present:
# https://github.com/golang/go/issues/4635
define Package/golang
$(call Package/golang/Default)
  TITLE+= (compiler)
  DEPENDS+= +golang-src
endef

define Package/golang/description
$(call Package/golang/Default/description)

This package provides an assembler, compiler, linker, and compiled
libraries for the Go programming language.
endef

define Package/golang/config
menu "Configuration"

config GOLANG_EXTERNAL_BOOTSTRAP_ROOT
	string "External bootstrap Go root directory"
	help
	  Path to a working Go tree (>= Go 1.4), with bin, pkg, and src
	  subdirectories and the Go compiler at bin/go.

	  If specified, the existing Go installation will be used to
	  compile host (buildroot) Go.

	  Leave blank to compile the default bootstrap Go.

endmenu
endef

define Package/golang-doc
$(call Package/golang/Default)
  TITLE+= (documentation)
endef

define Package/golang-doc/description
$(call Package/golang/Default/description)

This package provides the documentation for the Go programming language.
endef

define Package/golang-src
$(call Package/golang/Default)
  TITLE+= (source files)
endef

define Package/golang-src/description
$(call Package/golang/Default/description)

This package provides the Go programming language source files needed
for cross-compilation.
endef

EXTERNAL_BOOTSTRAP_DIR:=$(call qstrip,$(CONFIG_GOLANG_EXTERNAL_BOOTSTRAP_ROOT))
USE_DEFAULT_BOOTSTRAP:=$(if $(EXTERNAL_BOOTSTRAP_DIR),,1)

PKG_GO_ZBOOTSTRAP_MODS:= \
	s/defaultGO386 = `[^`]*`/defaultGO386 = `$(if $(GO_386),$(GO_386),387)`/; \
	s/defaultGOARM = `[^`]*`/defaultGOARM = `$(if $(GO_ARM),$(GO_ARM),5)`/; \
	s/defaultGOMIPS = `[^`]*`/defaultGOMIPS = `$(if $(GO_MIPS),$(GO_MIPS),hardfloat)`/; \
	s/defaultGOMIPS64 = `[^`]*`/defaultGOMIPS64 = `$(if $(GO_MIPS64),$(GO_MIPS64),hardfloat)`/; \
	s/defaultGOPPC64 = `[^`]*`/defaultGOPPC64 = `power8`/;

PKG_GO_LDFLAGS= \
	-buildid '$(SOURCE_DATE_EPOCH)'

ifeq ($(CONFIG_NO_STRIP)$(CONFIG_DEBUG),)
  PKG_GO_LDFLAGS+= -s -w
endif

# setting -trimpath is not necessary here because the paths inside the
# compiler binary are relative to GOROOT_FINAL (PKG_GO_ROOT), which is
# static / not dependent on the build environment
PKG_GO_INSTALL_ARGS= \
	-ldflags "all=$(PKG_GO_LDFLAGS)"

ifeq ($(PKG_GO_ENABLE_PIE),1)
  PKG_GO_INSTALL_ARGS+= -buildmode pie
endif

define Download/golang-bootstrap
  FILE:=$(BOOTSTRAP_SOURCE)
  URL:=$(BOOTSTRAP_SOURCE_URL)
  HASH:=$(BOOTSTRAP_HASH)
endef

$(eval $(call GoCompiler/AddProfile,Host,$(HOST_BUILD_DIR),$(HOST_GO_PREFIX),$(HOST_GO_VERSION_ID),$(GO_HOST_OS_ARCH),$(HOST_GO_INSTALL_SUFFIX)))
$(eval $(call GoCompiler/AddProfile,Package,$(PKG_BUILD_DIR),$(PKG_GO_PREFIX),$(PKG_GO_VERSION_ID),$(GO_OS_ARCH),$(PKG_GO_INSTALL_SUFFIX)))

ifeq ($(USE_DEFAULT_BOOTSTRAP),1)
  $(eval $(call GoCompiler/AddProfile,Bootstrap,$(BOOTSTRAP_BUILD_DIR),,bootstrap,$(GO_HOST_OS_ARCH)))

  $(eval $(call Download,golang-bootstrap))

  define Host/Prepare
	$(call Host/Prepare/Default)
	mkdir -p $(BOOTSTRAP_BUILD_DIR)
	$(BOOTSTRAP_UNPACK)
  endef
endif

# when https://github.com/golang/go/issues/31544 is fixed,
# we should be able to set GO_LDFLAGS=-buildmode=pie for host make
# instead of doing a rebuild for pie
define Host/Compile
	$(call GoCompiler/Bootstrap/CheckHost,$(BOOTSTRAP_GO_VALID_OS_ARCH))
	$(call GoCompiler/Host/CheckHost,$(HOST_GO_VALID_OS_ARCH))

	mkdir -p \
		$(BOOTSTRAP_CACHE_DIR) \
		$(HOST_GO_CACHE_DIR)

	$(call GoCompiler/Bootstrap/Make, \
		GOCACHE=$(BOOTSTRAP_CACHE_DIR) \
		CC=$(HOSTCC_NOCACHE) \
		CXX=$(HOSTCXX_NOCACHE) \
	)

	$(call GoCompiler/Host/Make, \
		GOROOT_BOOTSTRAP=$(if $(USE_DEFAULT_BOOTSTRAP),$(BOOTSTRAP_BUILD_DIR),$(EXTERNAL_BOOTSTRAP_DIR)) \
		GOCACHE=$(HOST_GO_CACHE_DIR) \
		CC=$(HOSTCC_NOCACHE) \
		CXX=$(HOSTCXX_NOCACHE) \
	)

  ifneq ($(HOST_GO_ENABLE_PIE),)
	@echo "Rebuilding host Go with PIE"

	( \
		cd $(HOST_BUILD_DIR)/bin ; \
		$(CP) go go-nopie ; \
		GOCACHE=$(HOST_GO_CACHE_DIR) \
		GOENV=off \
		CC=$(HOSTCC_NOCACHE) \
		CXX=$(HOSTCXX_NOCACHE) \
		./go-nopie install -a -buildmode=pie std cmd ; \
		retval=$$$$? ; \
		rm -f go-nopie ; \
		exit $$$$retval ; \
	)
  endif
endef

# if host and target os/arch are the same,
# when go compiles a program, it will use the host std lib
# so remove it now and force go to rebuild std for target later
define Host/Install
	$(call Host/Uninstall)

	$(call GoCompiler/Host/Install/Bin,)
	$(call GoCompiler/Host/Install/Src,)

	$(call GoCompiler/Host/Install/BinLinks,)

	rm -rf $(HOST_GO_ROOT)/pkg/$(GO_HOST_OS_ARCH)$(if $(HOST_GO_INSTALL_SUFFIX),_$(HOST_GO_INSTALL_SUFFIX))

	$(INSTALL_DIR) $(HOST_GO_ROOT)/openwrt
	$(INSTALL_BIN) ./files/go-gcc-helper $(HOST_GO_ROOT)/openwrt/
	$(LN) go-gcc-helper $(HOST_GO_ROOT)/openwrt/gcc
	$(LN) go-gcc-helper $(HOST_GO_ROOT)/openwrt/g++
endef

define Host/Uninstall
	rm -rf $(HOST_GO_ROOT)/openwrt

	$(call GoCompiler/Host/Uninstall/BinLinks,)

	$(call GoCompiler/Host/Uninstall,)
endef

define Build/Compile
	mkdir -p \
		$(PKG_GO_HOST_CACHE_DIR) \
		$(PKG_GO_TARGET_CACHE_DIR)

	@echo "Building target Go first stage"

	$(call GoCompiler/Package/Make, \
		GOROOT_BOOTSTRAP=$(HOST_GO_ROOT) \
		GOCACHE=$(PKG_GO_HOST_CACHE_DIR) \
		GO_GCC_HELPER_CC="$(HOSTCC)" \
		GO_GCC_HELPER_CXX="$(HOSTCXX)" \
		GO_GCC_HELPER_PATH=$$$$PATH \
		CC=gcc \
		CXX=g++ \
		PKG_CONFIG=pkg-config \
		PATH=$(HOST_GO_ROOT)/openwrt:$$$$PATH \
	)

	$(SED) '$(PKG_GO_ZBOOTSTRAP_MODS)' \
		$(PKG_BUILD_DIR)/src/cmd/internal/objabi/zbootstrap.go

	@echo "Building target Go second stage"

	( \
		cd $(PKG_BUILD_DIR)/bin ; \
		export $(GO_PKG_TARGET_VARS) ; \
		$(CP) go go-host ; \
		GOROOT_FINAL=$(PKG_GO_ROOT) \
		GOCACHE=$(PKG_GO_TARGET_CACHE_DIR) \
		GOENV=off \
		GO_GCC_HELPER_CC="$(TARGET_CC)" \
		GO_GCC_HELPER_CXX="$(TARGET_CXX)" \
		GO_GCC_HELPER_PATH=$$$$PATH \
		CC=gcc \
		CXX=g++ \
		PKG_CONFIG=pkg-config \
		PATH=$(HOST_GO_ROOT)/openwrt:$$$$PATH \
		./go-host install -a $(PKG_GO_INSTALL_ARGS) std cmd ; \
		retval=$$$$? ; \
		rm -f go-host ; \
		exit $$$$retval ; \
	)
endef

define Package/golang/install
	$(call GoCompiler/Package/Install/Bin,$(1)$(PKG_GO_PREFIX))
	$(call GoCompiler/Package/Install/BinLinks,$(1)$(PKG_GO_PREFIX))
endef

define Package/golang-doc/install
	$(call GoCompiler/Package/Install/Doc,$(1)$(PKG_GO_PREFIX))
endef

define Package/golang-src/install
	$(call GoCompiler/Package/Install/Src,$(1)$(PKG_GO_PREFIX))
endef

# src/debug contains ELF executables as test data
# and they reference these libraries
# we need to call this in Package/$(1)/extra_provides
# to pass CheckDependencies in include/package-ipkg.mk
define Package/golang-src/extra_provides
	echo 'libc.so.6'
endef

$(eval $(call HostBuild))
$(eval $(call BuildPackage,golang))
$(eval $(call BuildPackage,golang-doc))
$(eval $(call BuildPackage,golang-src))
